Example
json
{
"event_id": "event_5556",
"type": "response.function_call_arguments.done",
"response_id": "resp_002",
"item_id": "fc_001",
"output_index": 0,
"call_id": "call_001",
"name": "get_weather",
"arguments": "{\"location\": \"San Francisco\"}"
}response.mcp_call_arguments.delta
Returned when MCP tool call arguments are updated during response generation.